Lawrence Craven, a doctor from the USA, is the author of several published reports, one of _______ introduced the idea in 1953 _______ aspirin could reduce the risk of heart attacks.
In 2003, eBay, a famous website ________ people buy and sell things, said that 70 per cent of their problems were with people who sold things that did not exist, or who lied about the products they were selling.